IBM plsql - cursor

I am new with PLSQL (IDM db2) and I am trying to create a procedure to find and delete some admin_tasks if they exist.

Explanation: By running the bellow query1, I can find out the list of tasks in the scheduler:

SELECT * FROM SYSTOOLS.ADMIN_TASK_LIST;

To delete the task, I can run this query2:

call sysproc.admin_task_remove('TASK_NAME', null);

So I want to create a procedure to delete all tasks with the pattern "My_Task_*". This should delete all the tasks with that pattern and leave the other existent tasks intact. The procedure should handle cases where the admin_tasks doesn't exist, or no admin_tasks were ever created, and should run without throwing any errors.

I have researched and found out that this can be made using cursors.

Can you help me to implement this?

EDIT: I managed to find this solution:

BEGIN
  FOR v1 AS c1 CURSOR FOR
    SELECT NAME 
    FROM SYSTOOLS.ADMIN_TASK_LIST
    WHERE NAME LIKE 'My\_task\_%' ESCAPE '\'
   DO
    call sysproc.admin_task_remove(NAME, null);
  END FOR;
END

This seems to work except if the SYSTOOLS.ADMIN_TASK_LIST was not yet defined.

If it's not defined than I get this error when I run the query: If it is not defined I get this error : [Code: -204, SQL State: 42704]

"SYSTOOLS.ADMIN_TASK_LIST" is an undefined name.. SQLCODE=-204, SQLSTATE=42704, DRIVER=4.25.1301

So how can I bypass this error? DOing something like first checking if SYSTOOLS.ADMIN_TASK_LIST is defined, if its defined to the above query if not do nothing.

Solution

Presuming that your client tool uses '@' as a statement delimiter.

BEGIN
  FOR L1 AS 
    SELECT NAME 
    FROM SYSTOOLS.ADMIN_TASK_LIST
    WHERE NAME LIKE 'My\_task\_%' ESCAPE '\'
  DO
    CALL ADMIN_TASK_REMOVE (L1.NAME, NULL);
  END FOR;
END

Update:
With error handling for non-existing table. The error handler just "eats" the error on non-existing table use. You must use dynamic sql for that.

BEGIN
  DECLARE SQLSTATE CHAR (5);
  DECLARE L_NAME VARCHAR (128);
  DECLARE C1 CURSOR FOR S1; 
  DECLARE EXIT HANDLER FOR SQLSTATE '42704' BEGIN END;
  PREPARE S1 FROM 
    '
    SELECT NAME 
    FROM SYSTOOLS.ADMIN_TASK_LIST
    WHERE NAME LIKE ''My\_task\_%'' ESCAPE ''\''
    ';
  OPEN C1;
  L1:
  LOOP
    FETCH C1 INTO L_NAME;
    IF SQLSTATE = '02000' THEN LEAVE L1; END IF;
    CALL ADMIN_TASK_REMOVE (L_NAME, NULL);
  END LOOP L1;
  CLOSE C1;
END